I can't figure it out but I think it might be the Distributor but we'll see your opinion

my car CIVIC SI coupe 1998 (canadian version)
my engine is b16a 99-00 running a p28 ECU with a converting harnest from obd2 to obd1
my vtec only engage at 7800 RPM and the cut off online occurs at aroung 9800 RPM
I have tried 2 ECU my p28 and a p30 and also tried my p28 in an other card witch was working fine Vtec at 5500 and cut off at 8500

now what could be the cause of the vtec engaging so high ? I heard my distributor could be the problem cause I know it ain't my ECU cause that has been tested like I explained above and my tac i have a OEM one in dash

Can some one help me with this ?

 

im willing to bet you're p28 was previously chipped with god know's what kinda maps

 

^^^agreed

 

and i seriously hope you arent revving to 9800rpm with any frequency unless you have the valvetrain and bottom end work needed.

 

Like I said its not an ECU problem I have teste muliple ECU from stock p30 to chipped one they all do the same its like the engine does not care about the ECU settings all ECU i put in the vtec engage at 7800 rpm take the same ecu put it in an other car Vtec engage at 5500